Peter Norvig, director of research at Google Inc., stands for a portrait after a Bloomberg Television interview in San Francisco, California, U.S., on Thursday, March 17, 2011. Google aims to maintain the atmosphere of a start-up company within a big company to foster innovation, Norvig said. Photographer: David Paul Morris/Bloomberg *** Local Caption *** Peter Norvig
Peter Norvig, director of research at Google Inc., speaks during a Bloomberg Television interview in San Francisco, California, U.S., on Thursday, March 17, 2011. Google aims to maintain the atmosphere of a start-up company within a big company to foster innovation, Norvig said. Photographer: David Paul Morris/Bloomberg *** Local Caption *** Peter Norvig

Photo: David Paul Morris, Bloomberg

Peter Norvig, director of research at Google Inc., stands for a...

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Artificial Intelligence: A Modern Approach
(Third edition) by Stuart Russell and Peter Norvig

Photo: Prentice Hall

Artificial Intelligence: A Modern Approach
(Third edition) by...

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An ipad is used to call for a pick me up service for the driver less car "Made in Germany" (MIG), which from the outside looks like a regular Volkswagen Passat with a camera on top, is being put through its paces at Berlin's disused Tempelhof airport , October 13, 2010. German scientists unveiled the latest self-driving car, a phenomenon that its proponents say will sharply reduce accidents, help the environment and transform cities. The car, dubbed the "MIG" by its engineers at Berlin's Free University (FU), uses cameras, laser scanners and satellite navigation to "see" other vehicles and pedestrians and deal with traffic situations. AFP PHOTO / ODD ANDERSEN (Photo credit should read ODD ANDERSEN/AFP/Getty Images)
Ran on: 10-16-2010
AT&T will market Apple's iPad to AT&T's business customers. Verizon plans to sell the devices, too.

Students in this quarter's intro to artificial intelligence class at Stanford University will have a few options when it comes to cribbing notes. Like about 140,000.

The university is conducting what it calls a "bold experiment in distributed education" by offering the course for free to anyone interested. Tens of thousands snapped at the chance, overloading the servers when the class kicked off this week.

The heavy interest was no doubt due to the world-renowned AI experts teaching the course.

Peter Norvig is a former head of NASA's computer sciences division who is now director of research at Google, overseeing the Mountain View search giant's machine learning initiatives.

Sebastian Thrun is a Stanford research professor famous for heading the team that developed Stanley, the robotic car that won the 2005 DARPA Grand Challenge, a 132-mile driverless race through the Mojave Desert. He is now leading Google's autonomous car program.

The two are conducting the course in person for several hundred Stanford students - and through online videos, assignments and exams for everyone else. Internet participants will receive feedback and a statement of accomplishment, but no official credit or grades.

Norvig sat down with The Chronicle this week to discuss the decision to put the class online, the state of artificial intelligence and the ways that Google is pushing forward the field.

Q:Why did you decide to teach the AI course online this year?

A: My co-professor and I had taught the Stanford class last semester. We wanted to commit to doing it again, but we wanted to experiment. We thought, "We're putting a lot of effort into this, and there are a lot of Stanford students benefiting. But with a little more work, we could make this more widely available."

We thought there was a lot of interest out there, but we're definitely excited and a little shocked at the great interest. We've got 140,000 people signed up and they watched about a million videos on the first day.

Q:I read that Salman Khan, who runs the popular tutoring courses on YouTube, was an influence on the way you designed the class.

A: We had looked at what people had done in the past and had a slightly different take on what we thought was a good way of putting all those pieces together.

We'd seen things like the MIT OpenCourseWare, where they go into the classroom and record the professors. It's a good approach, but we thought there were a couple problems. We didn't think the hour-long lecture translates well to the laptop screen. It's harder to hold your attention over the computer, where you lose a bit of the immediacy of the classroom.

The other problem was the videos were available for download at any time, which means I can always put it off.

Why did I get my work done in college? It wasn't because I had terrific willpower; it was because I had a deadline.

So we want to bring that back in, to say, "You get the advantage of being in the class, but we're going to expect something of you. You're going to have to do homework, it's going to be due every Sunday, so you'd better watch the videos before that."

Q:We've heard about a lot of what are arguably AI breakthroughs in recent months. We had IBM's Watson beat human contestants at "Jeopardy." We have cars going increasingly longer distances at driving themselves. Are we at a point where the long-talked-about promise of AI is becoming a reality?

A: Maybe to the outside observer there are some of these milestones that look like they're breakthroughs that come out of nowhere.

But I see it as more of a continuation. We've been on this path for years, making steady progress, and now we're making more.

Q:There was long this notion of artificial intelligence as a brain in a box, a machine that could think like a human. We're nowhere close to that, but we do have computers that are getting increasingly good at specialized tasks. Do you think that's the model that AI will take, or are these building blocks toward that earlier conception of an all-around thinking computer?

A: Artificial intelligence is a big field. It encompasses a lot of different problems and a lot of different approaches. That includes the philosophy of what artificial intelligence is.

Some people have thought of it as duplicating a human brain. I tend to think of it as just building something that works.

(The late, influential computer scientist Edsger Wybe) Dijkstra said the question of whether machines can think is the same as whether submarines can swim. I don't care about whether you want to call it thinking or not, or intelligent or not, I just care that I can build something that solves a hard problem.

Q:What are the drivers of the AI advances we're seeing today?

A: The way we think about artificial intelligence has changed over the last few decades. Back in the '70s and '80s, we thought of AI as being personified by the "expert systems," where programmers and experts in certain fields get together and write down everything they know and try to encode it.

That worked to some extent, but the systems tended to be brittle for a couple reasons. One is that you couldn't interview a doctor about every possible scenario. So there were some things that weren't covered and the system didn't generalize well to something it hadn't seen before.

Since then, we've made advances in the theory of probabilistic reasoning, and we've made advances in machine learning. So (computers can now analyze huge amounts of) data and learn from it.

Q:I understand that the recent leaps forward in machine language translation, an area you're focused on at Google, were driven by using this approach.

A: Machine translation is a big area for us and it is an example of this shift. In the '70s and '80s, you'd hire a lot of linguists and have them make translation dictionaries and grammar rules and try to match all that up.

That approach only goes so far. There are always little exceptions that don't quite work. We trip the light fantastic, not the fantastic light. Why? Well, that's just the way it is.

So we needed these statistical correlations. We can't write down all the rules, so let's just observe language as it is, let's look at lots of examples of language texts and lots of examples of translations. And that proved to be more useful.

(Editor's note: Indeed, on Thursday, Google said its Translate app for Android phones can now translate 14 languages in a read-aloud "conversation mode," up from two. It can translate 63 languages in text.)

Q:It seems like AI is a consistent theme through much of Google's work, from the search engine to machine translation to autonomous cars. Is Google in some ways becoming an artificial intelligence company?

A: You can think of Google as being, in large part, an AI company. That's one way to look at it. I don't think everyone would use those words, but it's clear that Google is driven by data and by understanding and processing that data to improve.